Extension of Bischler-Napieralski reaction—I Synthesis of isoquinoline derivatives: A synthesis of rac.-apomorphine dimethyl ether

The scope of Bischler-Napieralski reaction has now been extended to include acyl cyclo-hexa-1:4-dienylethylamide types, which cyclise smoothly to yield various isoquinolines after dehydrogenation. 1-(2-Nitro-3:4-dimethoxybenzyl)-3:4-dihydroisoquinoline, hitherto difficultly accessible, could be prepared and converted to rac.-apomorphine dimethyl ether.     

Studies on the syntheses of heterocyclic and natural products. Part 979. Attempted asymmetric synthesis of yohimbol by photocyclization of the enamide

An asymmetric synthesis of yohimbane alkaloid has been attempted by the photolysis of the corresponding enamide ( 3 ) as a key reaction.     

Chiral phase transition in lattice QCD with Wilson quarks

The nature of the chiral phase transition in lattice QCD is studied for the cases of 2, 3 and 6 flavors with degenerate Wilson quarks, mainly on a lattice with the temporal direction extensionN _t=4. We find that the chiral phase transition is continuous for the case of 2 flavors, while it is of first order for 3 and 6 flavors.     

A character recognition system using a Φ-spatial filter

The results of experiments on character recognition, using a combination of Φ-spatial and band-pass filters, are reported. The experiments were made with fifteen classes of typewritten characters, with twenty-four classes of typewritten characters and with ten classes of handwritten characters.     

Ultra-small-angle neutron scattering studies on phase separation of poly(vinyl alcohol) gels

Time-resolved light scattering measurements during the gelation process of a poly(vinyl alcohol) (PVA) solution in a mixture of dimethyl sulfoxide and water (H2O) have shown that a spinodal decomposition (SD) type phase separation takes place in the early stage of gelation. In this case the kinetics of SD is valid only before macroscopic gelation occurs because the growth rate is slowed down by gelation. Such SD type phase separation makes the solution opaque as it proceeds, and hence the structural change can no longer be followed by light scattering. To investigate the structure of the opaque PVA gel as well, we have employed an ultra-small-angle neutron scattering technique using a Bonse-Hart camera. These observations reveal that even after the macroscopic gelation the structure due to the microphase separation on a spatial scale of several &mgr;m continues to grow against the elasticity. This may be because at first the gel structure is too soft to suppress the growth of the microphase separation, but within 24 h after the quenching the growth terminates. On the basis of the results, we will discuss a possible mechanism of the microphase separation after gelation.